Interest Calculator

Calculate simple or compound interest in seconds — enter the principal, rate and time to see the interest and total amount.

Files never uploadedNo sign-upWorks in your browserFree & unlimited

Interest: 40,000

Total amount (principal + interest): ₹1,40,000

Calculate interest in 3 simple steps

1

Choose the mode

Pick simple interest or compound interest, depending on what you need.

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2

Enter your numbers

Type the principal, the annual rate and the time period in years.

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3

See interest & total

Instantly view the interest earned (or owed) and the final maturity amount.

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Why use this interest calculator

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Simple & compound

Switch between both methods to see how much faster compounding grows money.

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Any compounding

Choose yearly, half-yearly, quarterly or monthly compounding for accuracy.

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FDs, savings & loans

Plan fixed deposits, savings growth, recurring loans or solve exam maths.

Instant & accurate

Uses the standard interest formulas — results update the moment you type.

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100% private

Your figures stay on your device; nothing is uploaded or stored.

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Free & unlimited

No sign-up, no limits — run as many calculations as you like.

Simple and compound interest, instantly

Interest is the cost of borrowing — or the reward for saving. Simple interest is calculated only on the original principal, while compound interest is calculated on the principal plus the interest already earned, so it grows faster over time. This tool handles both: switch the mode, enter your numbers, and choose how often interest compounds.

It is handy for fixed deposits, savings, recurring loans and exam maths problems alike. Everything is calculated locally in your browser.

Frequently asked questions

What is the simple interest formula?
Simple Interest = (Principal × Rate × Time) ÷ 100. It is calculated only on the original principal.
What is the compound interest formula?
Compound Interest amount = P × (1 + r/n)^(n×t), where P is principal, r is the annual rate (as a decimal), n is the compounding frequency per year, and t is the number of years. Interest earns interest over time.
What is the difference between simple and compound interest?
Simple interest is charged only on the principal, while compound interest is charged on the principal plus accumulated interest — so compound interest grows faster over long periods.
Is it free?
Yes — free, no sign-up, and it runs entirely in your browser.

By Narender Chaudhary, Editorial & Product Lead · Updated June 2026